<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./js/vue-2.4.0.js"></script>
    <style>
    .v-enter,
    .v-leave-to{
          opacity:0;
         transform:translateX(150px)
    }
    .v-enter-active,
    .v-leave-active{
        transition:all 0.8s ease;
    }

    
    </style>
</head>
<body>
    <div id="app">
          
            <input type="button" value="toggle" @click="flag =! flag">
        <transition>
            <h3 v-if="flag">这是一个H3</h3>
        </transition>
    </div>
</body>
<script>
  var vm = new Vue({
      el:'#app',
      data:{
      
        flag:true
      }
  })

</script>
</html>